Why is the Bradford assay important?
The Bradford assay for protein is widely used because of its sensitivity, speed, convenience, lack of need for a UV-capable spectrophotometer, and adaptability to 96-well plates. The “Bradford Reagent” is an acidic stain which turns blue when it interacts with protein.
How does the Bradford assay work?
The Bradford protein assay is used to measure the concentration of total protein in a sample. The principle of this assay is that the binding of protein molecules to Coomassie dye under acidic conditions results in a color change from brown to blue.
What is a BSA standard curve?
A standard curve is a plot of absorbance vs. a varying amount of some known concentration of protein. Two common proteins used for standard curves are bovine serum albumin (BSA) and an immunoglobin (IgG).
How long can you block a Western blot?
1 hr
Why do we block Western blots?
Blocking is a very important step of western blotting, as it prevents antibodies from binding to the membrane nonspecifically. The antibody can be diluted in a wash buffer, such as PBS or TBST. Washing is very important as it minimized background and removes unbound antibody.
Why is milk used for blocking?
Non-fat milk is one of the most common blocking agents used for Western blots. It contains a variety of proteins found in milk. Milk contains casein, a phosphoprotein that can be recognized by anti-phospho antibodies leading to non-specific binding and high background.
Do you need to wash after blocking?
General blocking procedures Sufficient washing after the blocking step is usually performed in order to remove excess protein that may prevent detection of the target antigen. However, many researchers do not wash after the blocking step because they dilute their primary antibodies in their blocking buffer.
What is blocking agent?
Blocking agents are compounds that inhibit the earliest phase of carcinogenesis through mechanisms that alter drug-metabolizing enzymes, trap cancer-producing compounds that react with activators of carcinogens and oxygen free radicals, and alter rates of DNA repair.